Aquaculture Nutrition. 2020;00:1–9. wileyonlinelibrary.com/journal/anu | 1 © 2020 John Wiley & Sons Ltd 1 | INTRODUCTION Aquaculture has become an important source of animal protein in the past decade (FAO, 2016; Little, Newton, & Beveridge, 2016). The rising demand of fish and shellfish has shifted the aquaculture practices from extensive fish farming towards intensive fish farming. Intensive aquaculture is favourable as it provides excessive fish, but chances of disease outbreak increase with the increasing stocking density (Cabello, 2006; Hoseinifar, Hosseini, et al., 2019; Hoseinifar, Van Doan et al., 2019; Romero, Gloria, & Navarrete, 2012). Overcrowding and poor water conditions result in immunosuppres- sion and outbreak of disease (Reverter, Bontemps, Lecchini, Banaigs, & Sasal, 2014). Several antimicrobial agents and vaccines are used to prevent disease outbreak and economic losses in aquaculture (Rico et al., 2013). Use of antimicrobial agents results in resistance and increased residues in fish muscles (Cabello, 2006). Therefore, there is a need for sustainable alternatives that can boost fish immune responses and help to increase disease resistance against various pathogens. Fish immune system consists of innate and adaptive sec- tions. Fish mucus is the first line of defence against pathogens. The major components of fish mucus are lysozyme, complement, peroxidases, proteases, antiproteases, esterases and antimicrobial peptides (Adel, Safari, Soltanian, Zorriehzahra, & Esteban, 2018). In pisces, head kidney, spleen and thymus are major immune or- gans that are involved in hematopoietic functions (Reyes-Cerpa et al., 2012). In addition, macrophages, neutrophils, mast cells and non-specific natural killer cells are major cells of innate immune Received: 20 September 2019 | Revised: 21 February 2020 | Accepted: 6 March 2020 DOI: 10.1111/anu.13073 ORIGINAL ARTICLE Dietary Moringa oleferia leaf meal induce growth, innate immunity and cytokine expression in grass carp, Ctenopharyngodon idella Mehwish Faheem 1 | Saba Khaliq 2 | Nazia Mustafa 1 | Sundas Rani 1 | Khalid P. Lone 1 1 Department of Zoology, GC University, Lahore, Pakistan 2 Department of Physiology and Cell Biology, University of Health Sciences, Lahore, Pakistan Correspondence Mehwish Faheem, Department of Zoology, GC University, Lahore, Pakistan. Email: mehwishfaheem@gcu.edu.pk Funding information ORIC. GC University (36/ORIC/19) Abstract The present research was designed to investigate the growth promoting and immu- nostimulating properties of Moringa oleferia leaf meal (MLM) in grass carp. Juvenile grass carp (22.03 g ± 1.164) were fed with diets supplemented with 0, 50, 100 and 150 g/kg MLM for 48 days. At the end of feeding trial, skin mucus was used for analysis of lysozyme, protease, antiprotease and peroxidase activity. Head kidney was used for expression analysis of tumour necrosis factor-alpha, interleukin-8 and interferon-γ. The obtained results showed that fish fed with 100 and 150 g/kg MLM had significant increase in weight gain and specific growth rate ( p < .05). However, condition factor was not altered. The MLM (50 and 100 g/kg) inclusion resulted in higher mucus lysozyme and protease activity ( p < .05), while peroxidase activity in- creased only in fish fed with 100 g/kg MLM and antiprotease activity was not altered. Expression of tnf-α increased in a dose-dependent manner, and significant ( p < .05) increase was recorded in fish fed with 150 g/kg MLM. The expression of il-8 and ifn-γ increased in fish fed with 50 and 150 g/kg MLM; however, the increase was not significant ( p > .05). In conclusion, supplementing juvenile grass carp feed with MLM up to 150 g/kg has growth promoting and immunostimulating effects. KEYWORDS fish health, grass carp, growth stimulator, innate immunity, Moringa oleferia